Thin film transistors (TFTs) are main driving components in current liquid crystal displays (LCDs) and active matrix organic light emitting diodes (AMOLEDs), and are directly related to a display performance of flat panel display devices.
Most of liquid crystal displays on the current market are backlight type liquid crystal displays, which include a liquid crystal display panel and a backlight module. Working principle of the liquid crystal display panel is to fill liquid crystal molecules between a TFT array substrate) and a color filter (CF) substrate, apply a pixel voltage and a common voltage on the two substrates respectively, and control a rotation direction of the liquid crystal molecules by an electric field formed between the pixel voltage and the common voltage to transmit light of the backlight module to generate a picture.
According to different structures, touch display panels can be divided into on-cell type touch display panels, in-cell type touch display panels, and externally-attached type touch display panels. The externally-attached type touch display panels are to make a touch sensor on a surface of a color filter, and the touch sensor is added with glass to form a touch panel module, and then a liquid crystal panel module is attached. The in-cell type touch display panels are formed by a touch sensor in a panel structure, and the touch sensor is directly placed in a thin film transistor liquid crystal display panel module, and a touch function is integrated in a display, such that a touch panel does not need to be externally mounted, a thickness thereof is also lighter and thinner than a thickness of an externally-attached type touch panel, which can effectively avoid an adverse effect of the externally-attached type touch panel on optical characteristics and a thickness of the panel. Due to an increasing of a display screen ration, a lower border of a display panel is getting smaller and smaller, and a space of a metal fan-out traces of output pins of the panel connected to an interlace IC and touch signal lines and data signal lines of a display area (active area, AA) is reduced. (Interlaced integrated chip refers to a type of IC with embedded touch drive function. The order of output pins of this type of IC is that output pins of data signals and output pins of touch signals are alternately wired according to a certain rule.) This leads to a reduction in a line width of the metal fan-out traces, which is liable to cause metal fan-out wire breakage and affect the panel touch function.